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Business Intelligence

What does API mean and how does it function

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Seongbin

2025년 7월 07일

An API, or application programming interface, lets two different applications talk to each other. You use APIs every day, often without even knowing it. When you order food at a restaurant, you tell the waiter what you want. The waiter takes your request to the kitchen and brings back your meal. APIs work just like that waiter. They carry your request from one application to another and return the response. APIs help software communicate and transfer data, making things like mobile payments and social media logins possible. In fact, over 62% of programmers now rely on APIs, and this number keeps growing.

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Key Takeaways

  • APIs act like messengers that let different apps talk and share data quickly and safely.
  • Most apps use APIs to get information, like weather updates or social media logins, without showing the complex details behind the scenes.
  • APIs follow clear rules and use requests and responses to send and receive data between applications.
  • There are different types of APIs—open, private, and partner—that serve various needs from public use to secure business connections.
  • Good API documentation helps developers use APIs correctly, saving time and avoiding errors during integration.

API Meaning

Application Programming Interface

You see the term "application programming interface" often in technology. It may sound complex, but it describes a simple idea. An application is any software you use, like a weather app or a banking tool. A programming interface is a set of rules that lets one application connect with another. When you use your phone to check the weather, your weather app uses an API to get the latest data from a weather service. The API acts as a bridge, making sure your application can talk to other systems safely and quickly.

APIs have changed how you interact with technology. They help different applications work together, even if they were built by different companies. You can log in to a new website using your social media account because APIs allow secure sharing of your information. This process saves you time and keeps your data safe.

Tip: When you use an app that pulls information from another service, you are likely using an API—even if you do not see it working in the background.

API Definition

Application and API integration.png
API integration of FineDataLink

An API is a set of rules and tools that lets one application communicate with another. You can think of it as a menu at a restaurant. The menu lists what you can order, but you do not see how the kitchen prepares your food. In the same way, an API tells your application what it can ask for and how to ask for it, but it hides the complex details behind the scenes.

APIs have evolved over time. Researchers have studied how APIs change and how these changes affect software. Here are some key findings from their work:

  • Laerte Xavier and others studied how changes in APIs can impact software, showing how important it is to keep APIs stable.
  • S. M. Sohan and his team looked at how web APIs change over time, giving real-world examples of API evolution.
  • Erik Wittern and colleagues discussed the challenges of using APIs and how these challenges shape software development.
  • Other studies have explored how developers use APIs and how API rules change, helping everyone understand the growth of API technology.
  • Reviews of research show that API evolution has a big impact on how software grows and improves.

You can see the impact of APIs in many industries. Companies use APIs to speed up development, improve user experience, and save money. Hospitals use APIs to share patient data and improve care. Banks use APIs to make payments safer and faster. Here is a table that shows some real-world results:

Sector/CompanyMeasurable ImpactDescription
Tech Company30% reduction in time-to-marketCentralized API management platform streamlined development, accelerating feature delivery.
Tech Company20% increase in user satisfactionImproved API monitoring and optimization enhanced user experience and satisfaction.
Tech CompanySignificant operational cost savingsOptimized resource allocation and reduced inefficiencies lowered operational expenses.
Healthcare Hospital15% improvement in care coordinationAPI integration using FHIR standard enabled better patient data exchange and treatment.
Healthcare HospitalReduction in administrative burdensStreamlined data sharing reduced paperwork and manual processes.
Financial ServicesEnhanced transaction processing and securityAPIs integrated with payment and fraud detection systems to improve reliability and compliance.

APIs help you get new features faster, enjoy better apps, and trust that your information stays secure. Every time you use an application that connects to another service, you benefit from the power of APIs.

How API Works

Request and Response

You interact with APIs every time you use an application that connects to another service. The process starts when you make an api request. Imagine you open a weather app and want to see today’s forecast. Your app sends a request to a weather service’s api endpoint. This endpoint is like a specific address where the weather data lives. The api call travels over the http protocol, which is the standard way computers talk on the web.

The api request contains details about what you want. The weather service receives your request, processes it, and sends back a response. This response usually comes in a format like JSON or XML. Your app reads the response and shows you the forecast. This whole process is called the request-response cycle.

You can think of the api as a waiter in a restaurant. You (the user) make a request by ordering food. The waiter (the api) takes your order to the kitchen (the server) and brings back your meal (the response). You never see the kitchen’s inner workings, just like you never see the code behind the api.

Most modern applications use rest apis. These apis use the http protocol to send and receive data. Each api call goes to a specific endpoint, which acts like a menu item. You can make many types of api requests, such as GET (to read data), POST (to add data), PUT (to update data), or DELETE (to remove data). Each type of request tells the api what action you want to perform.

Here is a simple step-by-step breakdown of how apis enable communication between software:

  1. You identify the data source, such as a database or an external service.
  2. You send an api request to the correct endpoint using http.
  3. The api receives your request and checks if you have permission.
  4. The api processes your request and gathers the needed data.
  5. The api sends a response back to your application.
  6. Your application displays the information to you.

Tip: Every time you log in to a new app using your social media account, you are making an api call. The app sends an api request to the social media platform, which returns a response with your profile information.

Statistical studies show that following a clear process for api-based data synchronization leads to better results. Companies that use modern apis see a 25% increase in data synchronization efficiency and a 30% reduction in manual effort. You can see these improvements in the chart below:

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You can use different synchronization methods with apis:

  • Batch synchronization for periodic updates.
  • Real-time synchronization for instant data updates.
  • Bidirectional synchronization for two-way data sharing.
  • Change Data Capture (CDC) to transfer only changed data.
  • API-based synchronization for direct, seamless data transfer.

Interface Structure

The interface of an api acts as a set of rules that tells your application how to communicate with another system. Each api has endpoints, which are specific paths or addresses where you send your api requests. The interface defines what data you can request, how you should format your request, and what kind of response you will get.

Most rest apis use the http protocol. You send api requests to endpoints using http methods like GET, POST, PUT, or DELETE. The api responds with data, status codes, or error messages. This structure makes it easy for developers to understand how apis work and to build reliable applications.

Here is a table that shows the main parts of an api interface:

Part of API InterfaceDescriptionExample
EndpointThe address where you send your api request/weather/today
HTTP MethodThe action you want to performGET, POST, PUT, DELETE
Request HeadersExtra information sent with your api requestAuthentication tokens, content-type
Request BodyData you send with your api requestUser details, search parameters
ResponseThe data or message you get backWeather data, status code

When you use rest apis, you often make multiple api calls to different endpoints. Each api call follows the same pattern: send a request, get a response. The http protocol ensures that your data travels safely and quickly between systems.

FanRuan and FineDataLink use apis to help organizations integrate and synchronize data in real time. FineDataLink lets you build an api interface in just a few minutes, even without writing code. You can connect over 100 data sources, automate data flows, and keep your business data up to date. The platform uses rest apis and the http protocol to make sure your api requests and responses move smoothly between systems. This approach reduces manual work, improves data quality, and helps your business make faster decisions.

data integration.jpg
data integration of FineDataLink

Note: FineDataLink’s visual interface makes it easy to set up api endpoints and manage api calls. You can monitor your api requests, track responses, and ensure your data stays synchronized across all your applications.

API Examples

Real-World Use Cases

You interact with APIs every day, often without realizing it. Many applications rely on APIs to handle your requests and deliver the right response. Here are some real-world examples of APIs that you probably use:

  • Social Media Logins: When you sign in to a new app using your Facebook or Google account, the app sends a request to the social media platform’s API. The API checks your information and sends back a response with your profile details.
  • Weather Apps: You open a weather app and see the forecast. The app makes a request to a weather service API, which returns the latest weather data. This is a real example of an api in action.
  • Payment Gateways: When you buy something online, the website sends a request to a payment gateway API. The API processes your payment and sends a response confirming your purchase.
  • Maps and Navigation: Many navigation applications send a request to a mapping API to get directions or traffic updates.
  • Messaging Apps: When you send a message, the app uses an API to deliver your request to the recipient and receive a response.

These real-world examples of apis show how APIs connect different applications and services. Each request you make triggers a process that brings back the information or service you need.

FineDataLink Integration

FineDataLink by FanRuan gives you a powerful way to connect your applications and share data across systems. You can build an API interface in minutes, even if you do not write code. FineDataLink supports over 100 data sources, so you can send a request from one application and get a response from another system quickly.

Enhanced data connectivity.png
Enhanced data connectivity of FineDataLink

Here are some api examples of how FineDataLink helps you:

Use CaseRequest ExampleResponse Example
Real-Time Data SyncApplication A sends a request for new recordsApplication B sends updated data
Data SharingBI tool requests sales data from ERP systemERP system returns sales data
Automated ReportingScheduler requests daily report dataSystem responds with report file

You can automate your data flows and keep your applications up to date. FineDataLink makes it easy to manage each request and response, so your business runs smoothly. These real-world examples of apis highlight how FineDataLink streamlines integration and boosts efficiency.

Tip: FineDataLink’s visual interface lets you monitor every request and response, making data integration simple for all your applications.

API Types

When you explore the world of APIs, you find several types that serve different needs. Understanding the different types of apis helps you choose the right one for your project or business. Each type offers unique benefits and plays a key role in software development.

Open and Private APIs

Open APIs, sometimes called public APIs, are available for anyone to use. You can access them without special permission. Many companies use open APIs to encourage innovation and speed up development. For example, you might use an open API to connect your app to a weather service or a map provider. Open APIs often use the http protocol, making them easy to integrate with web applications.

Private APIs work differently. Only people inside a company or organization can use them. You might use a private API to connect internal systems, such as linking your sales database to your reporting tools. Private APIs help keep sensitive data secure and support custom development within your business. Both open and private APIs rely on http to send and receive data.

You can measure the performance of open and private APIs using several important metrics. These metrics help you track the benefits and reliability of your API connections:

Performance MetricDescription and Relevance to Usage Patterns in Business Environments
Availability / UptimeMeasures service reliability and user access continuity, critical for both open and private APIs to maintain trust and engagement.
Response Time / LatencyIndicates speed of API responses, affecting user satisfaction and system efficiency across API types.
Request RateReflects load and usage patterns, helping identify peak times and user behavior for both open and private APIs.
Error RateTracks frequency and severity of errors, providing insight into reliability and potential issues impacting API users.
CPU and Memory UsageShows resource utilization, helping optimize infrastructure supporting API performance regardless of API openness.
Unique User CountReveals user engagement and distinguishes between single-user vs multiple-user activity, important for usage analysis.
Cache Hit RateAssesses caching efficiency, impacting performance and cost optimization in API delivery.

Note: Monitoring these metrics helps you improve the benefits of apis and ensures your systems run smoothly.

Partner APIs

Partner APIs sit between open and private APIs. You share them with selected partners or clients, not with the public. You might use a partner API to let a trusted business access your inventory or order system. This type of API supports collaboration and helps you build strong business relationships.

You often use http to connect with partner APIs, just like with other types. Partner APIs offer many benefits. They help you control who accesses your data, support secure data sharing, and speed up joint development projects. You can use partner APIs to create new services, improve customer experiences, and unlock new business opportunities.

When you understand the different types of apis, you can make better choices for your development projects. Each type brings unique benefits, from open innovation to secure internal connections and trusted partnerships.

API Documentation

Importance of Documentation

You need clear documentation to understand how APIs work. Good documentation acts like a map. It shows you where to start, what you can do, and how to avoid mistakes. When you try to connect different software, you often rely on api documentation to guide you. If the documentation is confusing or missing, you may waste time or make errors.

Many developers face problems when documentation is not clear. The table below shows how important documentation is for successful API integration:

Statistic DescriptionPercentage
Developers citing inconsistent documentation as biggest roadblock to API integration39%
Developers relying on internal documentation for API integration58%
Developers relying on colleagues to explain APIs (causing delays)44%

You can see that almost four out of ten developers struggle when documentation is not consistent. More than half depend on internal documentation to get their work done. If you want to avoid delays, you should always look for thorough api documentation before starting a project.

Using API Docs

You can use api documentation to learn how to use an api, test requests, and solve problems. Most documentation gives you step-by-step guides, code samples, and explanations for each endpoint. This helps you understand what data you need to send and what you will get back.

When you use api documentation, you benefit from:

  • Usability metrics like time to complete tasks, error rates, and navigation efficiency. These show how easy it is to find and use information in the documentation.
  • Customer satisfaction metrics from surveys and feedback forms. These reflect how happy users feel with the documentation.
  • Good navigation in documentation reduces frustration and support requests. Poor navigation causes confusion and slows you down.
  • Usability testing and direct feedback help improve documentation over time.
  • Accessible and thorough documentation increases satisfaction and lowers support costs.

You should always check the documentation before you start building. This helps you avoid mistakes and saves time. If you use a platform like FineDataLink, you will find detailed documentation that explains every step. This makes it easier to connect your data and keep your systems running smoothly.

Tip: Always bookmark the api documentation for any service you use. This makes it easy to find answers and stay productive.

You see APIs at work every day, connecting applications and making your digital experiences seamless. APIs let your applications share data, automate tasks, and deliver new features quickly. Modern integration strategies rely on APIs to create secure, scalable, and innovative applications. Businesses now use APIs to improve decision-making, reduce costs, and boost productivity. FineDataLink helps you integrate applications and manage data in real time. As you use more applications, you benefit from faster onboarding, better fraud detection, and smarter data solutions. APIs will continue to shape the future of applications and business integration.

Click the banner below to experience FineDataLink for free and empower your enterprise to convert data into productivity!

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FAQ

What is an API in simple terms?
You can think of an API as a messenger. It lets two different apps talk to each other and share information. You use APIs every day when you check the weather or log in with your social media account.
How do APIs keep your data safe?
APIs use security methods like authentication tokens and encryption. You only get access if you have permission. This keeps your personal data protected when apps communicate.
Can you use APIs without knowing how to code?
Yes! Many platforms, like FineDataLink, offer visual tools. You can connect data sources and set up API integrations with simple drag-and-drop actions. You do not need to write any code.
Why do businesses rely on APIs?
APIs help businesses connect systems, automate tasks, and share data quickly. You can improve efficiency, reduce manual work, and deliver better services to customers by using APIs.
What makes FineDataLink’s API integration special?
You can build and launch an API interface in minutes with FineDataLink. The platform supports over 100 data sources and uses a visual interface. This makes data integration fast, easy, and accessible for everyone.
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Seongbin

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